wifi: ath12k: fix invalid access to memory

In ath12k_dp_rx_msdu_coalesce(), rxcb is fetched from skb and boolean
is_continuation is part of rxcb.
Currently, after freeing the skb, the rxcb->is_continuation accessed
again which is wrong since the memory is already freed.
This might lead use-after-free error.

Hence, fix by locally defining bool is_continuation from rxcb,
so that after freeing skb, is_continuation can be used.

Compile tested only.

Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
Signed-off-by: Sarika Sharma <quic_sarishar@quicinc.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Link: https://patch.msgid.link/20250408045327.1632222-1-quic_sarishar@quicinc.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath12k/dp_rx.c b/drivers/net/wireless/ath/ath12k/dp_rx.c
index 40feaa6..3db1470 100644 (file)
--- a/drivers/net/wireless/ath/ath12k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath12k/dp_rx.c
@@ -1841,6 +1841,7 @@ static int ath12k_dp_rx_msdu_coalesce(struct ath12k *ar,
        struct hal_rx_desc *ldesc;
        int space_extra, rem_len, buf_len;
        u32 hal_rx_desc_sz = ar->ab->hal.hal_desc_sz;
+       bool is_continuation;
 
        /* As the msdu is spread across multiple rx buffers,
         * find the offset to the start of msdu for computing
@@ -1889,7 +1890,8 @@ static int ath12k_dp_rx_msdu_coalesce(struct ath12k *ar,
        rem_len = msdu_len - buf_first_len;
        while ((skb = __skb_dequeue(msdu_list)) != NULL && rem_len > 0) {
                rxcb = ATH12K_SKB_RXCB(skb);
-               if (rxcb->is_continuation)
+               is_continuation = rxcb->is_continuation;
+               if (is_continuation)
                        buf_len = DP_RX_BUFFER_SIZE - hal_rx_desc_sz;
                else
                        buf_len = rem_len;
@@ -1907,7 +1909,7 @@ static int ath12k_dp_rx_msdu_coalesce(struct ath12k *ar,
                dev_kfree_skb_any(skb);
 
                rem_len -= buf_len;
-               if (!rxcb->is_continuation)
+               if (!is_continuation)
                        break;
        }